A large number of medical diagnostic and therapeutic procedures involve percutaneous introduction of instrumentation into a blood vessel. For example, coronary angioplasty, angiography, atherectomy, stenting, and numerous other procedures often involve accessing the vasculature through placement of a catheter or other device in a patient's femoral artery or other blood vessel. Once the procedure is completed and the catheter or other diagnostic or therapeutic device is removed, bleeding from the resultant vascular puncture must be stopped.
Traditionally, a medical practitioner applies external pressure to the percutaneous entry site to stem bleeding until hemostasis has occurred (i.e. when the clotting and tissue rebuilding have sealed the puncture). This method, however, presents numerous problems. In some instances, this pressure must be applied for up to an hour or more during which time the patient is uncomfortably immobilized. In addition, there exists a risk of hematoma, since bleeding from the puncture may continue until sufficient clotting affects hemostasis. Furthermore, application of external pressure to stop bleeding may be unsuitable for patients with substantial amounts of subcutaneous adipose tissue, because the skin surface may be a considerable distance from the puncture site, thereby rendering external compression less effective.
Another traditional approach to subcutaneous puncture closure involves internally suturing the vessel puncture. This method, however, comprises a complex process and requires considerable skill by the medical practitioner.
Mechanical occlusion devices have been proposed for sealing vascular punctures in U.S. Provisional Patent Application Ser. No. 60/400,658, filed Jul. 31, 2002, which describes a closure device having two expandable disks that sealingly compress a vessel or tissue surrounding the puncture site. Advantageously, the two disks may be repositioned post-deployment at the puncture without inflicting additional trauma to the engaged vessel or tissue.
Apparatus and methods also are known in which a plug is introduced into the vessel puncture, to cover the puncture and promote hemostasis. Various types of plugs have been proposed. One example is described in U.S. Pat. No. 5,061,274 to Kensey, comprising a plug made from animal-derived collagen. Such a plug inserted into the puncture may be dislodged into the vessel during the healing process due to the application of pressure to the wound, potentially causing stenosis of the vessel. Furthermore, the presence of the plug within the puncture prevents re-access to the puncture site without potentially dislodging the plug into the vessel. Further still, there is a risk of unwanted adverse reaction to the animal-derived collagen.
In view of the drawbacks associated with prior art methods and apparatus for sealing a vascular puncture, it would be desirable to provide apparatus that overcomes such drawbacks.
It would be desirable to provide apparatus for sealing a vascular puncture by inducing a reduction in the circumference of the puncture.
It also would be desirable to provide apparatus for sealing a vascular puncture that reduces a potential that a portion of a wound closure device will protrude into the vessel lumen.
It further would be desirable to provide apparatus for sealing a vascular puncture that is easy to use.
It even further would be desirable to provide apparatus for sealing a vascular puncture that permits re-access to the puncture site.
It still further would be desirable to provide apparatus for sealing a vascular puncture that are biodegradable.